Acne is an often chronic inflammatory disease of the sebaceous glands and is one the most common skin diseases on the plant, affecting at least 650 million people. Four out of five Americans between the ages of 12 and 24 develop at least one or more forms of acne, and scientists and dermatologists still struggle to explain the cause and to develop treatments. According to the American Academy of Dermatology, there are multiple forms of acne, ranging in severity from unsightly, bothersome, and common comedones, including blackheads, whiteheads, and pimples, to more serious problems that may include bacterial infections in papules, nodules, and cysts.
The sebaceous glands are typically located on the face, scalp, and back and secrete an oily or waxy substance called sebum that lubricates the hair and skin and improves barrier functions of the skin. A comedone is a basic acne lesion and occurs when a hair follicle becomes plugged with sebum and with skin debris, including dead skin cells. A blackhead occurs when the pore is open and the oil inside the pore is exposed to the air, oxidizes, and turns black. Blackheads vary in size and appear on the skin as black or grey spots. Whiteheads, which are not exposed to the air because the opening of the hair follicle is blocked with sebum and dead skin cells, appear as white bumps on the skin. The cosmetic industry has a number of remedies for extracting and removing blackheads and whiteheads, yet they often reoccur.
Another type of acne includes papules, which are comedones that have become inflamed and turn red. Pustules are a more severely infected type of inflamed pimple. The pustule is usually characterized by an inflamed bump that is filled with white or yellow pus. Severe forms of acne may also include cysts, which are large lesions that are pus filled and resemble boils. These more serious types of acne can lead to permanent scarring and even disfigurement.
Given the high occurrence of incidents of acne and the potential for serious consequences, medications and methods have been developed to reduce and combat acne breakouts. Medications have focused on three methods: 1) over-the-counter medications typically containing benzoyl peroxide or salicylic acid, in a topical delivery vehicle, including, for example, creams and gels; 2) topical retinoid prescription medications based on derivatives of Vitamin A and that may include the compounds tretinoin, which is a carboxylic acid of Vitamin A; tazarotene, which is a prodrug of the carboxylic acid of tazarotene; and adapalene, another topical retinoid; and 3) oral or topical prescription antibiotics including tetracycline and erythromycin among others. Although most of these compounds are capable of reducing the incidence of acne and some may also reduce the severity of an acne occurrence, each of them can have undesirable side effects, including adversely impacting the skin.
Salicylic acid and benzoyl peroxide can dry the skin and cause peeling and irritation of the stratum corneum, which is the highly differentiated outermost layer of the skin. Even more serious, the Food and Drug Administration (FDA) recently issued a Drug Safety Communication (DSC) to inform consumers and health care professionals of the potential dangers of certain acne products containing the active ingredients benzoyl peroxide or salicylic acid. The FDA warned that benzoyl peroxide and salicylic acid can cause rare, but serious and potentially life-threatening allergic reactions or severe irritation. The FDA warning was precipitated by the agency receiving reports from both consumers and manufacturers of allergic and hypersensitivity related adverse reactions associated with these over-the-counter (OTC) products. The reports contain incidents of throat tightness, shortness of breath, wheezing, low blood pressure, fainting or collapse.
Although the side effects of topical OTC products normally are listed on their labels, including a caution that if the side effects become too severe, the user should stop application and contact a physician, the FDA noted in their DSC that there is currently no mention of the possibility of very severe allergic reactions on the labels of acne products containing benzoyl peroxide and salicylic acid.
Prescription topical medications used for the treatment of acne typically are much more powerful than topical OTC medications, and they can also cause very serious incidents of skin drying, flaking, and redness. Sunscreen may be required because some OTC's increase sensitivity to sunburn. Prescription topical medications for the treatment of acne containing tazarotene can cause serious birth defects. Women are cautioned to avoid having children while prescribed drugs containing tazarotene.
Prescription antibiotics can be used to treat acne. However, concerns exist among many that antibiotics are overused, causing increases in antibiotic resistance, which means that the antibiotics are less effective at killing or controlling the bacteria that causes acne, as the bacteria can become resistant to the antibiotic.
Generally speaking, it is recognized that treatments that adversely impact the skin, and including the outermost layer, the stratum corneum, which is a complex organ of many functions, need to be improved. For example, Marks, R., in “The Stratum Corneum Barrier: The Final Frontier,” published in 2004 in the American Society for Nutritional Sciences, pages 2017S through 2021S, notes that healthy stratum corneum is highly efficient in its multiple barrier functions at restricting the movement of water in and out of the body and in precluding penetration of chemical agents. Damaged stratum corneum is said to be capable of losing up to 6 liters of water per day by transepidermal water loss and may allow ingress of chemical agents and pathogens.
Formation of the outer layer of the epidermis is a complex process often referred to as “keratinization.” Keratinization is characterized by, among others, water loss and a reduction in pH from the inner to outermost stratum corneum layer, the development of thin overlapping horn cells called corneocytes, specialized cross-linked proteins that are highly chemical resistant, and specialized non-polar lipids that provide a water barrier property. The constant outward movement of corneocytes to be sloughed off at the surface in the process of an orderly desquamation of individual keratinized cells is said to be a built-in mechanism to preclude pathogens from gaining a foothold. Impairment of desquamation, as when the binding force between corneocytes increases under stress and causes the cells to desquamate in clumps, is often characterized as scaling, as in eczema and psoriasis.
Treatments that interfere with the processes of keratinization and desquamation of the stratum corneum inevitably damage the stratum corneum functions, including water and chemical barrier functions, promoting scaling, redness, and pruritus, and decreasing flexibility.
Ali, S. M. and Yosipovitch, G. in “Skin pH: From Basic Science to Basic Skin Care,” published Jan. 16, 2013 in Vol. 93 of Acta Dermato Venereologica at pages 261 to 267, posits generally that in managing skin diseases including acne, use of soaps and creams that do not compromise the acidic pH of the skin should become part of the treatment regimen and that the ideal cleanser has a pH of between 4.5 and 6.5, similar to normal skin. Frequent use of alkaline soaps is said to cause irritation and the article discloses the desirability of preserving or restoring an acidic milieu by using agents compatible with the acid mantle to restore barrier function when the barrier function is faulty. However, no specific alternative cleansers or treatments are recommended for any particular skin disease and there is little data confirming an innate impairment of the stratum corneum permeability barrier in acne vulgaris. See, Del Rosso, J. Q. and Levin, Jacqueline, “The Clinical Relevance of Maintaining the Functional Integrity of the Stratum Corneum in both Healthy and Disease-affected Skin,” published September 2011 in the Journal of Clinical Aesthetic Dermatology, Vol. 4, issue 9, at pages 22 to 42.
It would be desirable to develop specific alternative methods and products for reducing the incidence and severity of one or more forms of acne that do not have or at least reduce the drawbacks associated with the above-described prevalent treatments and products.